Exams should be tests of the more important stuff that people learn, the general concepts, the big ideas, the take home messages, more than being a matter of testing for how much trivia has been closely packed and soon to be discarded. Because of this exams will have choices and allow students to provide information that they do know to illustrate the concepts that are important.
Learning some basic facts is still important so don't over look them. However, don't spend all of your time memorizing facts and missing the point of the course which is learning how to solve problems in the field of medical ethnobotany.